Member phone and email test.
Datetime testing.
Initialising
Added support for position invitations.
Added support for inviting all members through the EventRole is_open variable.
Merge branch 'inviteposition'

This merges a couple of features into master: Being able to invite members of a particular position (on-call, in training, etc.) as well as all members to an event.
  https://github.com/ZmjbS/tsar/issues/49